In this paper we present some particular designs for transmission subtransinission , and lines that located in special conditiotis such as high & snowy districts that there are many mechanical & eleciticalfailvvires in winters , safty problems of OHTLs that located in urban , limitations Of requiered righ of way for many new lines and dijfitculties & limitations of ereetiing normal distribution lines on montain areas , so that as in these sitvatioins normal de.~vigrnns include many difffiicultie, & limitalions on erection & main tenance of T / Ls . These new designs are rm,lted frrotn our research & exvpetietice, of erection & maintenance of T I Ls, at last ten year.v, on some special districts of Es/ahan & Charmohal - bakhtiari provinces and the results were completely safifactory .

كلمات كليدي: